Bringing this discussion back to the "ext4: introduce per-inode DAX
flag" patch, it sounds to me that I should _not_ apply this patch
until we figure out to fix this for reals.  Does this sound fair?

If we think it's completely unfixable, then maybe XFS should consider
(temporarily) withdrawing the per-file DAX support before there is a
userspace and you have to support it forever, but that's between the
NVM/dax and XFS folks to figure out.

					- Ted